The invention relates to an apparatus for sensing the load-dependent variable distance between an axle and the body of a motor vehicle, including a system of rods fastened to the vehicle axle and a modulator, actuated by these rods, which controls the supply of a pressurized medium to an auxiliary power system through a control line.
Such an apparatus for an auxiliary powered beam-aiming control for the headlights of motor vehicles is known (Press photograph No. 4622 of Robert Bosch GmbH, Stuttgart KH/VDT 7.73). In this known apparatus, the modulator is a control valve which monitors the alternative communication of a servo-member with either a supply of pressurized air or with the atmosphere.
It is also known to use the above-described apparatus in an auxiliary powered brake-force controller for a motor vehicle braking system which can be adjusted in dependence on load. See, for example, German Auslegeschrift 1,271,567. The known brake force controller is used in vehicles having steel springs and controls the braking pressure in a load-dependent manner when the springs are stressed.